why is a p value of 10^-7 given as less than 0.05?

I just searched my protein mass spec data againts the mascot data base.

to determine significants mascot says that a score of 70 has a p<0.05

it also gives the formula of

score= -10 log (P) , where P is the probability that the observed match is a random event.

From my understanding, that would mean that 70 corresponds to p=10^-7 which would mean that p<0.001.

any idea why they didnt express it as p<0.001 ?